Pneumatic relay

ABSTRACT

A fluid valve operative based on a pressure differential through the utilization of different size pressure receiving piston faces. A first fluid, through pressure on an enlarged piston face, maintains a valve spool so shifted as to allow for a through passage of a second fluid. Upon a blocking of the first fluid, the second fluid, acting on a relatively smaller valve surface, actuates the valve and blocks through passage of the second fluid. The shifting of the valve presents yet a smaller pressure receiving face to the first fluid which, in conjunction with an exhaust port, provides a fail safe lock out requiring manual resetting of the relay.

Theriot et al.

1 PNEUMATIC RELAY [75] Inventors: Gerold F. Theriot, Bourg; Frank M.

Hoofnagle, Houma, both of La.

[73] Assignee: B. W. B. Controls, Inc., Houma, La.

[22] Filed: Sept. 6, 1973 [21] Appl. No.: 394,849

[52] US. Cl l37/625.66; 137/458 [51] Int. Cl. Fl6k 17/00 [58] Field ofSearch 137/456, 458, 464,466, 137/625.66

[56] References Cited UNITED STATES PATENTS 2,871,876 2/1959 Edmund137/464 2,879,789 3/1959 Towler et a1 137/456 3,621,881 11/1971 Vicari137/458 12/1972 Paulivkonis ..137/625.66 6/1973 Kaemmer l37/625.66

Primary ExaminerRobert G. Nilson [57] ABSTRACT A fluid valve operativebased on a pressure differential through the utilization of differentsize pressure receiving piston faces. A first fluid, through pressure onan enlarged piston face, maintains a valve spool so shifted as to allowfor a through passage of a second fluid. Upon a blocking of the firstfluid, the second fluid, acting on a relatively smaller valve surface,actuates the valve and blocks through passage of the second fluid. Theshifting of the valve presents yet a smaller pressure receiving face tothe first fluid which, in conjunction with an exhaust port, provides afail safe lock out requiring manual resetting of the relay.

13 Claims, 3 Drawing Figures Bleed Parr Aclualor Supp y High Low P170!Can/r0! Fluid pp y PNEUMATIC RELAY The present invention is generallyconcerned with pneumatic relays or fluid valves of the type utilized inconjunction with an automatic actuator for a gas or oil well line tocause the actuator to shut the well in should the pneumatic supply beblocked for any reason.

More particularly, the invention is concerned with a relay whichoperates solely on pressure differential, utilizing only a single movingpart so as to provide a simple and trouble free unit which is unique inboth structure and operation.

In conjunction with the above, the relay or valve incorporates apressure controlled lock out which is fail safe in operation,particularly when compared to the more conventional spring-operated pinlock out devices which operate erratically and frequently fail underactual operating conditions.

Basically, the relay or valve of the invention is installed upstream ofan automatic actuator and includes an elongated valve memberlongitudinally shiftable within a valve body basically between a firstposition allowing through passage of actuator fluid from a supply to theactuator, and a second position closing off the actuator supply andbleeding the actuator itself. Movement of the valve member is controlledbasically by the presence or absence of a control fluid pressure inconjunction with different pressure receiving areas on the selectivelyexposed valve member or piston faces.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

FIG. 1 is a vertical cross-sectional view through the relay of theinvention positioned within a schematically illustrated system;

FIG. 2 is a similar cross-sectional view of the relay with the valvemember shifted to a flow terminating position; and

FIG. 3 is a partial sectional view illustrating the safety lockoutconcept of the invention.

Referring now more specifically to the drawings, reference numeral isused to generally designate the relay or valve comprising the invention.As will be appreciated from FIG. 1, the relay, in the contemplatedenvironment, will be positioned on the upstream side of an automaticactuator 12 utilized to shut in a gas or oil well should the pneumaticsupply be blocked for any reason.

The relay 10 itself includes an elongated body 14 having a central bore16 therethrough which slidably receives the,valve member 18.

The valve member 18 projects beyond one end of the body 14 and isprovided with a manipulating head or handle 20 thereon, an appropriatesealing ring 22 precluding the escape of fluid from the bore 16 at thisfirst end of the body 14.

A fluid bleed port 24 is provided in communication with the bore 16inward of the first end of the body 14. An outlet port 26, whichcommunicates with the actuator 12, is provided inward of the bleed port24 and also communicates with the central bore 16. An actuator fluidinlet port 28 is provided inward of the outlet port 26 and communicatesthe actuator fluid supply 30 with the relay 10. Finally, an exhaust port32 is provided inward of the inlet port 28. The second end of the body14 is closed by a plug 34 which has a small control fluid inlet port 36therein communicating with a relatively small cylindrical valve seat 38incorporating an O-ring seal 40.

The valve member 18 is provided with a first bore wall engaging O-ringseal 42 peripherally thereabout at a point selectively shiftable frombetween the bleed port 24 and outlet port 26, so as to allow for athrough passage of the actuator fluid from the inlet 28 to the outlet 26and actuator 12, and a second inwardly shifted position between theinlet 28 and the outlet 26 precluding flow therebetween while openingcommunication between the outlet 26 and bleed port 24 for a bleeding ofthe fluid from the actuator 12.

Immediately below or inward of the inlet port 28, the bore 16 iscylindrically enlarged, as indicated by reference numeral 44, theexhaust port 32 communicating with this enlarged bore portion 44 at theend thereof remote from the inlet port 28.

That portion of the valve member 18 within the enlarged bore portion 44,is also cylindrically enlarged as indicated by reference numeral 46,presenting an enlarged piston or pressure receiving face 48 directedtoward the intake port 28 with an appropriate bore wall engaging O-ringseal 50 provided peripherally thereabout inward of the piston face 48.

The bore 16, below the exhaust port 32, or toward the second end of thevalve body 14, is again cylindrically outwardly enlarged, as indicatedby reference numeral 52. The valve member 18 is similarly enlarged,presenting a substantially greater piston face or pressure receivingface 54 directed toward the second end of the valve body 14 and thecontrol fluid inlet 36. This further enlarged or piston portion of thevalve member 18 also carries a peripheral sealing ring 56 which engagesthe wall of the bore portion 52. The bore 16 terminutes, immediatelyinward of the valve seat 38, in a further slightly enlarged portion 58into which the last mentioned enlarged piston portion of the valvemember 18 moves, breaking the sealed engagement of the sealing ring 56with the bore wall as will be readily appreciated from FIGS. 2 and 3.The extreme end of the valve member 18 is provided with a greatlyreduced cylindrical end portion 60 which seats within the end valve seat38 into sealing engagement with the sealing ring 40 provided therein.

It is contemplated that the actuator fluid be supplied at a pressure ofpounds while the control fluid be supplied at a pressure ofapproximately 30 pounds. In operation, assuming the manually setposition of FIG. I, the pressure of the control fluid on the enlargedpiston or pressure receiving face 54 is sufficient so as to retain thevalve member 18 in its extended position as illustrated in FIG. 1,providing a through passage for the actuator fluid from the supply tothe actuator, the piston face 48 seating against the shoulder definedbetween the main bore portion and the first enlarged bore portion 44.With the pressure receiving face 48 seated against the bore definedshoulder, it will be appreciated that the surface presented to thegreater actuator fluid pressure is substantially reduced with thedifference between the area of this face and the area of the face 54receiving the control fluid pressure being specifically sized so as toresult in a greater axial pressure on the face 54 and retention of thevalve member 18 in the position of FIG. 1. It will be noted that in thisposition, the seal 42 closes off the bleed port 24 from both the inletand outlet ports.

Should the control fluid be blocked, or the pressure thereofsubstantially reduced for any reason, the pressure on the face 54 isimmediately decreased and the now greater pressure on the face 48 movesthe valve member 18 inwardly, seating the reduced area end valve portion60 within the valve seat 38 and at the same time closing communicationbetween the inlet port 28 and the outlet port 26 so as to terminate flowto the actuator while at the same time opening communication between theoutlet port 26 and the bleed port 24 so as to bleed the actuatorpressure out of the relay l and, through the automatic operation of theactuator, cause the gas or oil well to shut in.

Once the relay has closed, it is essential that it not reopen until themalfunction which caused the initial closing be corrected. In otherwords, it is extremely important that the relay remain closed untilspecifically manually reset, regardless of reinstitution of theinitially controlling pressures. In effecting this, it will be notedthat with the valve portion 60 seated within the valve seat 38 over thesmall inlet port 36, only an extremely small pressure receiving surfaceis presented even should the original control fluid pressure return,this surface being substantially less than the surface 48 now fullypresented to the substantially greater actuator fluid pressure as willbe readily appreciated from FIG. 2, thereby avoiding substantially anypossibility of the valve member 18 shifting to its activated position ofFIG. 1.

As yet a further safeguard, and in order to make the relay fail safe inoperation, provision is also made for a situation wherein the actuatorfluid pressure is lost in conjunction with a restoration of the controlfluid pressure. Such an unusual circumstance would normally result in areturn of the valve member 18. However, the reduced size of the controlfluid inlet port 36, in conjunction with the enlarged exhaust port 32and the fluid passing space about the largest lower valve member portionprovided by the enlarged bore portion 58 provides for a directexhausting of any entering control fluid subsequent to a movement of thevalve member 18 sufficiently so as to break the seal between the valvemember portion 60 and the seal within its seat 38. The relative sizes ofthe exhaust port 32, inlet port 36 and fluid path suggested by thearrows in FIG. 3 is obviously to be such as to provide for a completeexhausting of any fluid pressure which might be produced in a situationas just described whereby a further closing movement of the valve member18 is specifically precluded. In this manner, a positive lock-out isprovided without requiring any mechanical latches, springs, lockpins orthe like with the lock-out being substantially fail safe in operation.

From the foregoing, it should be appreciated that a highly uniquepneumatic relay or fluid valve has been defined. This valve incorporatesonly a single moving part yet provides for a complete control, includinga lock-out feature which accommodates any foreseeable circumstanceeffectively and simply without in anyway affecting the manual resettingof the relay.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

what is claimed as new is as follows:

1. A valve comprising a valve body, an elongated bore within said body,a first fluid inlet port, an outlet port, a bleed port, a second fluidinlet port, a valve member slidable within said bore, said valve memberpresenting a first pressure surface on said valve member exposed to saidfirst fluid inlet port, a second pressure surface on said valve memberexposed to said second fluid inlet port, said valve being selectivelyshiftable between a first position allowing communication between thefirst fluid inlet port and the outlet port and precluding communicationbetween the outlet port and the bleed port, and a second positionallowing communication between said outlet port and said bleed port andprecluding communication between said first fluid inlet port and saidoutlet port, a greater total force on said second pressure surface thanon said first pressure surface maintaining said valve member in saidfirst position, a greater total force on said first pressure surfacethan on said second pressure surface moving said valve to said secondposition, and means for effectively precluiding fluid pressure suppliedsaid valve through said second fluid inlet port from moving said valvefrom said second position to said first position, said precluding meansincluding a) an exhaust port in fluid communication with said secondfluid inlet port only when said valve member is in a further positionintermediate said first and second positions, and b) seal meanspreventing fluid communication between said exhaust port and said secondfluid inlet port when said valve member is in said first and secondpositions.

2. A valve comprising a valve body, an elongated bore within said body,a first fluid inlet port, an outlet port, a bleed port, a second fluidinlet port, a valve member slidable within said bore, said valve memberpresenting a first fluid pressure surface on said valve member exposedto said first fluid inlet port, a second fluid pressure surface on saidvalve member exposed to said second fluid inlet port, said valve memberbeing selectively shiftable between a first position allowingcommunication between the first fluid inlet port and the outlet port andprecluding communication between the outlet port and the bleed port, anda second position allowing communication between said outlet port andsaid bleed port and precluding communication between said first fluidinlet port and said outlet port, a greater total force on said secondpressure surface than on said first pressure surface maintaining saidvalve in said first position, a greater total force on said firstpressure surface than on said second pressure surface moving said valveto said second position, a valve seat about said second fluid inletport, said valve member including a portion thereon receivable withinsaid seat to close said second fluid inlet port upon movement of thevalve member from the first position thereof to the second position, andan exhaust port selectively communicated with said second fluid inletport when said valve member isin a position intermediate said first andsaid second position.

3. The valve of claim 2 wherein said second pressure surface is of asubstantially greater area than said first pressure surface.

4. The valve of claim 3 wherein said seat received valve portionpresents a pressure receiving face directed toward said second fluidinlet port which has a substantially smaller area than said firstpressure surface.

5. The valve of claim 4 wherein said valve member projects outwardlybeyond a first end of said valve body for a manual gripping andmanipulation thereof.

6. The valve of claim 5 wherein said second fluid inlet port is definedin the second end of said body, said bore and said valve memberextending longitudinally through said body between the first and secondends thereof.

7. The valve of claim 6 wherein said outlet port is laterally directedthrough said body in inwardly spaced relation to said first end, saidfirst inlet fluid port being laterally directed through said body ininwardly spaced relation to said outlet port.

8. The valve of claim 7 wherein said bleed port is laterally directedthrough said body between said first end and said outlet port.

9. The valve of claim 8 wherein said valve member includes a first boreengaging seal which, in the first position of the valve member, isorientated between the outlet port and the bleed port, and in the secondposition of the valve member is orientated between the outlet port andthe first fluid inlet port.

10. The valve of claim 9 wherein said exhaust port is laterally directedthrough said body between the second end of the valve body and the firstfluid inlet port.

11. The valve of claim 10 wherein said first pressure receiving surfaceon the valve member is orientated between the first fluid inlet port andthe exhaust port, and bore engaging seal means about said valve memberat said first pressure receiving surface.

12. The valve of claim 11 wherein said second pressure receiving surfaceon said valve member is orientated between the exhaust port and thesecond fluid inlet port, and bore engaging seal means about said valvemember at said second pressure receiving surface.

13. The valve of claim 12 wherein said bore is of a constant diameter,engageable by the first bore engaging seal, between the first end of thebody and a point just beyond the first fluid inlet port, said boresubsequently being enlarged to a point just beyond the exhaust port andsealingly engaged by the seal at the first pressure surface, said borebeing further enlarged beyond the exhaust port and sealingly engaged bythe seal at the second pressure surface, said bore, inward of the secondfluid inlet port, being of a diameter greater than that of the secondpressure surface and seal thereabout so as to selectively provide afluid passage from the second fluid inlet port to the exhaust port.

1. A valve comprising a valve body, an elongated bore within said body,a first fluid inlet port, an outlet port, a bleed port, a second fluidinlet port, a valve member slidable within said bore, said valve memberpresenting a first pressure surface on said valve member exposed to saidfirst fLuid inlet port, a second pressure surface on said valve memberexposed to said second fluid inlet port, said valve being selectivelyshiftable between a first position allowing communication between thefirst fluid inlet port and the outlet port and precluding communicationbetween the outlet port and the bleed port, and a second positionallowing communication between said outlet port and said bleed port andprecluding communication between said first fluid inlet port and saidoutlet port, a greater total force on said second pressure surface thanon said first pressure surface maintaining said valve member in saidfirst position, a greater total force on said first pressure surfacethan on said second pressure surface moving said valve to said secondposition, and means for effectively precluiding fluid pressure suppliedsaid valve through said second fluid inlet port from moving said valvefrom said second position to said first position, said precluding meansincluding a) an exhaust port in fluid communication with said secondfluid inlet port only when said valve member is in a further positionintermediate said first and second positions, and b) seal meanspreventing fluid communication between said exhaust port and said secondfluid inlet port when said valve member is in said first and secondpositions.
 2. A valve comprising a valve body, an elongated bore withinsaid body, a first fluid inlet port, an outlet port, a bleed port, asecond fluid inlet port, a valve member slidable within said bore, saidvalve member presenting a first fluid pressure surface on said valvemember exposed to said first fluid inlet port, a second fluid pressuresurface on said valve member exposed to said second fluid inlet port,said valve member being selectively shiftable between a first positionallowing communication between the first fluid inlet port and the outletport and precluding communication between the outlet port and the bleedport, and a second position allowing communication between said outletport and said bleed port and precluding communication between said firstfluid inlet port and said outlet port, a greater total force on saidsecond pressure surface than on said first pressure surface maintainingsaid valve in said first position, a greater total force on said firstpressure surface than on said second pressure surface moving said valveto said second position, a valve seat about said second fluid inletport, said valve member including a portion thereon receivable withinsaid seat to close said second fluid inlet port upon movement of thevalve member from the first position thereof to the second position, andan exhaust port selectively communicated with said second fluid inletport when said valve member is in a position intermediate said first andsaid second position.
 3. The valve of claim 2 wherein said secondpressure surface is of a substantially greater area than said firstpressure surface.
 4. The valve of claim 3 wherein said seat receivedvalve portion presents a pressure receiving face directed toward saidsecond fluid inlet port which has a substantially smaller area than saidfirst pressure surface.
 5. The valve of claim 4 wherein said valvemember projects outwardly beyond a first end of said valve body for amanual gripping and manipulation thereof.
 6. The valve of claim 5wherein said second fluid inlet port is defined in the second end ofsaid body, said bore and said valve member extending longitudinallythrough said body between the first and second ends thereof.
 7. Thevalve of claim 6 wherein said outlet port is laterally directed throughsaid body in inwardly spaced relation to said first end, said firstinlet fluid port being laterally directed through said body in inwardlyspaced relation to said outlet port.
 8. The valve of claim 7 whereinsaid bleed port is laterally directed through said body between saidfirst end and said outlet port.
 9. The valve of claim 8 wherein saidvalve member includes a first bore engagiNg seal which, in the firstposition of the valve member, is orientated between the outlet port andthe bleed port, and in the second position of the valve member isorientated between the outlet port and the first fluid inlet port. 10.The valve of claim 9 wherein said exhaust port is laterally directedthrough said body between the second end of the valve body and the firstfluid inlet port.
 11. The valve of claim 10 wherein said first pressurereceiving surface on the valve member is orientated between the firstfluid inlet port and the exhaust port, and bore engaging seal meansabout said valve member at said first pressure receiving surface. 12.The valve of claim 11 wherein said second pressure receiving surface onsaid valve member is orientated between the exhaust port and the secondfluid inlet port, and bore engaging seal means about said valve memberat said second pressure receiving surface.
 13. The valve of claim 12wherein said bore is of a constant diameter, engageable by the firstbore engaging seal, between the first end of the body and a point justbeyond the first fluid inlet port, said bore subsequently being enlargedto a point just beyond the exhaust port and sealingly engaged by theseal at the first pressure surface, said bore being further enlargedbeyond the exhaust port and sealingly engaged by the seal at the secondpressure surface, said bore, inward of the second fluid inlet port,being of a diameter greater than that of the second pressure surface andseal thereabout so as to selectively provide a fluid passage from thesecond fluid inlet port to the exhaust port.